Photographic stencil material



June 11, 1940. MURRAY 2,204,147

7 PHOTOGRAPHIC STENCIL MATERIAL Original Filed May 24, 1934 v W I-"Ill"mmvzm 68. 74% kam' A TTURNEYS.

Alexander Murray Patented June 11', 1940 UNIT A srArss- 2,204,147 7 v Iruo'rocasrmc STENCIL MATERIAL Alexander Murray, Rochester,N.'Y.,assignor, by I mesne assignments, to Eastman KodakOompany, JerseyCity, N. .L, a corporationof New Jersey Application December "1, 1935,Serial No. 53,381,

which is a division of Serial No. 727,304, May 24, 1934. Divided andthis application January 22, 1938, Serial E0. 183,413

'3Claims.

This invention relates to a photographic element which may be used formaking etched designs on glass and metal objects, such as bowls',tiukmblers, vases, cylinders, stem-ware, and the This case is a divisionof application Serial No. 53,381, died December '1, 1935, now Patent2,158,194, whichintiirn is a division 0! applica tion Serial No.727,304, filed May 24, 1934, now

l0 Patent 2,073,313. 7

It has been diflicult to make deeply etched or cut designs of uniformlyhigh quality upon the surface of solid objects such as stem-ware, ex-

. cept by processes requiring a large amount of 15-: time consumingandhighly skilled hand work.

I have invented av method of etching such glasswere in a simple andcomparatively inexpensive manner. This comprises the formation on afreely extensible sheet, such as rubber, of an'image go that isextensible with the rubber and applying this image bearing stencil ornegative, preferably in the, form or a closed or tubular band, to

the surface of the object to be etched, which also carries a sensitivecoating. This is then exposed.

g5 tofiuniform illumination from all sides, the'negative removed, andthe glass or metal etched by a photoengraving process. i

' My invention resides in the various methods herein described of makingthe elastic stencil, in

30 the sensitized elastic element, and in thecom:

pleted elastic stencil band, I 1

"Referencewill be made to the accompanying drawing. n the severalfigures of which like numerals represent like parts and in which:

a Fig.1 is, a section on 5-3-11 exaggerated scaleof a sensitized elementmade according to my inven tion.'

Fig, 2 is a similar section of the element after 'xposure and removal ofthe resist at the exfpo'sedportions.

Fig; 4' is a section cation of a' 'dye' thereto. Fig. 515 asection ofthe elastic sheet bearing the dye design, after removal from thesupport.

' 1"ig, 6"is a perspective view of a frame can?- ing' an endlessrubberstencil strip;

' .nament'ed. e 4

Fig. 8 is a similar view showing'the gobletand band inposition torprinting.

It is obvious that a prime desideratum in 'a photographic negative orstencil having a highly Fig, 3, is a section of theelementfafteretching.

of the element after appliilexible'or elastic is thattheiuiage shall bemust be printed or stenciled upon thesupport I:

itself and the original layer removed;

. I will first describe my preferred method oi forming such a stencil ornegative, reference ber, ing made tcFlg. 1.

Upon a suitable support I which may be a glass plate, a sheet of acellulosic derivative composition, waxed or otherwise waterprooied,cardboard or any other reasonably rigid sheetga thin, elastic, soft,translucent, vulcanized rubber sheet 2 is temporarily attached by meansof a suitable stripping adhesive, such as wax or a rubber cement.'I'herubber sheet would be held smoothly but ordinarily not undertension. Asuitable cement is a .5% solution of rubber inbenzene.

Commercial rubber sheeting having a thickness of .003-.004 inch ispreferred but the thickness may vary within wide limits, as between.0005 and .Ollnch. I

A thin, preferably unelasticstencil material v3, as for instance, asheet of brass, nickel or other metal foil .001 inch thick, is thenattached) to the rubber layer by means of a rubber cement. If theelement is tobe used immediately, brass is preferred, but since brasstends to affect rubber if kept in contact with it, nickel or some otherinert material would be used if the plate is to be stored for some time.i p To the shetof -foil 3' is then applied ,a coatingl'o! a lightsensitive resist, an example being the following:

.Granis.

- Dicinnamal acetone 32.5"

' Theresist mentioned is of" thetype covered in my prior Patent No.1,965,7l0, granted .lulylO, 1934, and forms-a hard coherentcoat ing w LA line negative. or positive is placed in. contact with" the sensitive.coating andexposed-to the Iflg. "I is a similar view showing the bandex- 1 pended to permit insertion of a goblet to'be or-- light of, 30ampere arc lamp at a distance of, 24 inches for 5 minutes. The unexposedpartsiof the resist arep'removed by treatmentv withkerosene; The solventaction, is'ccntrolled by observation and is stopped by removal ofthekero- 'sene'by washingwith soap andwater. The .ele-

ment'afterthistreatment-is illustratedin Fig.2, theiresist-bein'gindicated by 4'.

, The stencil sheet is then etched in the exposed parts of the designwith aqueous ferric chloride solution of above 36 Baum until the brassis removed to the rubber which the etching solution does not aifect. Theelement then appears as shown in Fig, 3, the etched brass sheet beingindicated at 3'. l

After rinsing with water and drying, the etched surface is treated witha stain, solution or dye which deposits upon the areas of rubber laidbare by etching, a' coloring matter which becomes physically extensiblewith the rubber, as indicated at 5 in Fig. 4. This may be a rubber in orstain, sprayed or brushed upon the stencil and coating the rubber in thestencil openings. This solution may consist of:

. Grams Nogrosine (Schulz No. 985) 5 2% crepe rubber in benzene 30 Etherg 65 The resist areas would also be more or less colored, but. no use ismade of this property, as it is merely incidental. The stencil foilsheet carrying the resist is readily stripped from the rubber bystripping the a rubber sheet from the support and then stretching it,whereupon the inextensible foil, not

stretching with the rubber and being attached thereto by astripplngdayer, separates from it.

Photo-engraving glue (fish glue) grams 360 Ammonium bichromate do 55Water "liters-.. 1

When dry, the plate is exposed to a suitable light design, the printdeveloped by washing in water, and dried. It is now covered with asuitable stain such as the one already described, or

Grams Oil Red 0 dye (Schulz No. 532) 1 Nigroslne 4 1.0% rubber solutionin benzene 20 When dry, the rubber sheet is stripped from. the

temporary support and washed in warm water to remove the remaining glue.This is aided by stretching the rubber. There is left a rubber sheetcarrying a stain, which ordinarily will be a line image.

A thirdmethod, which is non-photographic, of,

making the rubber negative or sitive will now be given. The rubber sheetis p aced over a design to be copied. The rubber sheet may be eithermounted on afglass sheet as before or placed 1 tightly on the designon adrawing board and both held in place by th tacks. The design or patternis then drawn i water color on the rubber by hand using a suitable finebrush, When dry it is stained with dye solutions of the type al- .readydescribedi The water color is then washed off leaving the stain image.

Still a fourth method is'the following. A rubber sheet; mounted asbefore, is coated with a silver halide-gelatine emulsion, exposed to avlight image, of the design, and developed in a tanning developer ofknown type, such as pyro. The untanned gelatine is removed by-washing inwarm water.. After drying the negative is stained as 1 above describedand the remaining tanned gelatine stencil removed by any usual, meansthat does not attack the rubber or the stain.

By whichever method is used. there is obtained an elastic -negative, thesupport-of which is a thin, elastic, soft, translucent, anized sheet ofrubber carrying a perfectly exte sible design in animated cartoons, maybe made by constantly changing the extension of the rubber in one ormore directions or unevenly. If extended uniformly in all directions, anenlarged print may be made by direct contact printing.

By stretching to a precisely determined de-. gree, a negative havingcalibration marks on it may be used in the calibration of individualinstrument scales where the samescale readings are shown but in somewhatdifferent dimensions on the .several instruments. I

The principal use which I have in mind, however, is the printlng ofphotographicdeslgns upon thesurface of an object having other than aplane surface. Such objects may be glassware, such as bowls, tumblers,jars, stem-ware including go'blets, wine glasses and vases, and otherdishes; metal cylinders used in printing processes or for any otherpurpose; molded metal forms, such as picture frames, convex dials, watchcases and furniture parts and other objects toonumerone to catalog. Ingeneral the printing would be made by stretching the negative over oraround the object to be ornamented or marked and which would carry uponits surface a. light sensitive coating. The rubber sheet would by itsown tension hug closely and contact the surface of the object, exceptfor concavities. The first photographic image could'be the permanent oneif the object werenot to be subjected to rough usage but the coatingusually would be of a type adapted to act as a resist, and afterexposure, would be developed by a wash-oil or solvent process, leaving aresist design through which a suitable etching fluid could act on themetallic or glass object, after which the resist would be removed. Theparticular resist used would have to be one capable of withstanding theetching fluid used. Many such are known for use with metallic surfacesbut few photographic resists are known prior to my invention capable ofwithstanding the action of hydrofluoric acid ordinarily used for glassetchina.

Reference will now be made to Figs. 6, 7 and 8 which show a device forapplying the negative to the surface of an object such as a goblet. .Anegative strip l0 bearing a repeat design II, has its ends secured by asuitable rubber cement in an air tight seam l2, thus forming an endlessor cylindrical rubber negative, the size of which, when unextended, isless than the article to be etched or ornamented. The edges of thisnegative are secured between clamping blocks of a suitable frame. Thisframe consists of a glass cylinder is having tightly fitting metal orrubber annular rings i4 and IS in its opposite ends. These rings havecut out annular rabbets within which fit smaller rings IS on their outersurfaces. The ring it is removed from ring it and, while one edge of thenegative band is held stretched,

is replaced, clamping the edge between the rings II and It. The otheredge of the band is then clammd to the ring II in a similar way. Thenormal position of the band is shown in Fig. 6. Through the ring itpasstwo tubes H and is, with stop cocks I! and 20,. the first tube beingconnected to a source (not shown) of compressed air or, preferably, ot acompressed inert gas and the other to-a suction device (not-shown), orboth may be connected to a circulating supply of an inert cooling fluid.When the stop cock 2.

is opened and the cock it closed, air. will be withdrawn from theannular space between the glass cylinder II and the rubber negative IIand the latter will be drawn outwardly as shown in Fig. "I. The goblet2i or other article carrying a sensitive coating on that portion of itssurface to be ornamented is then placed within the casing as shown inthe same figure and stop cock is opened while 20 is closed.

Even if the tube H were open to the air, the contraction of the rubbernegative band ll would ordinarily cause it to contact closely with thesurface of the goblet, but in order to insure uhisform close contactthroughout, the tube I1 is preferably connected to a source of,compressed air, and this is necessary if the article. to be marked hasconcavities in its surface or if the article has portions of somewhatsmaller diameter than the normal diameter of the band i I.

Since the exposures are made under rather high light and heatconditions, the rubber, if conflnuously expos d, tends to deterioraterapidly.

lbrthisreasonlprefertouseaninert fiuid' rather than air and to circulatethis through the space between the rubber negative and the glasscylinder. 'niis fluid may be an inert gas or a liquid such as water.

The whole device containing the mac n is then rotated at a uniform ratebefore a light source for as long a time. as may be required for theexposure, depending on the intensity of the light and sensitivity of theparticular coating on the article if. The light passes through the glasswhich is unobstructed and through the negative producing a print on thesensitized siu'face.

l. A method of making upon a thin sheet of translucent, elastic rubberan image strongly adherentthereto and capable of contracting andexpanding therewith that comprises holding said rubber sheet with itssurface smooth,. applying a metallic resist material to saidsheet,applying a photographic layer to said resist material, forming a stencilrelief image in the photographic layer, treating the material with asolvent for the resist material which removes such resist material whereexposed through the photographically formed stencil, then applying tothe rubber areas thus laid bare a stain capable of adhering to therubber. and capable of contracting and expanding therewith, and thenremoving the remaining portions of the resist and photographic layers.

2. A method of making an imageupon a thin sheet of translucent, elasticrubber carrying a layer of metallic resist material and a sensitivephotographic layer. thereon that comprises forming photographicallyastencil image in the last with such surface and then removing the re-{naming portions of the resist and photographic ayers.

3. A method of making an image upon a .thin sheet oftranslucent,'elastic rubber carrying a removable layer of a metal foiland a sensitive photographic layer thereon, that comprises formingphotographically a stencil image in the last named layer, laying bareportions of the metal foil, submitting the surface to a chemical agentwhich attacks the foil but not the photographic layer nor the rubberwhereby. the portions of foil laid bare through the photographicallyformed stencil are removed, submitting the surface to a solutionincluding dye, rubber and a volatile solvent for rubber whereby there isformed on the portions of the rubber surface laid bare through so thefoil and photographic layers a dye image firmly adherent to the rubberand freely distortable with the rubber, and then removing the remainingportions of the foil and photographic layers.

smxsnnm stunner.

